The conventional usual injection is contained in an ampoule or vial. In injection, first, the ampoule is cut, or rubber cap of the vial is bored to absorb the injection liquid, and thereafter the injection is given to a patient. In this case, the syringe is disposed so that a single syringe needle is not used for plural persons, thereby preventing infection of bacteria.
Usually, usually, a single injection is carried out as described above. As the case may be, however, a mixed injection of two or more injections is carried out in the injection for treatment of, for example, knee-joint arthritis, shoulder-joint arthritis. Injection of only the hyaluronic acid natrium as a treatment medicine gives a patient a severe pain. To moderate the pain, hydrochloric acid lidocaine as local anesthesia is mixed with the hyaluronic acid.
Specifically, first, the ampoule is cut to absorb hyaluronic acid contained therein into a syringe. Next, using the syringe needle, the rubber stopper of a vial is bored to absorb the hydrochloric acid in the syringe. Thus, two injections are mixed. This mixed injection is injected into the affected part. Two or more injections are also mixed in the case where freeze-dried material such as antibiotic, steroid, vaccine, etc. or powder filler is sealed in a vial, and its solution or diluted solution is contained in an ampoule. In this case, first, the ampoule is cut to absorb the solution contained in the ampoule into a syringe. The syringe needle is thrust through the rubber stopper of a vial to inject the solution within the syringe into the vial. The syringe needle is once pulled out from the rubber stopper. The vial is shaken to dissolve the freeze-dried material. The syringe needle is again thrust through the rubber stopper to absorb the solution into the syringe. Thereafter, a patient is given the injection.
In the injection manners as described above, persons engaged in medical treatment may be injured by pieces of glass of the ampoule in cutting the ampoule. Then, infection or contagion of hepatitis or AIDS may also occur owing to bleeding. When the ampoule is cut, minute fragments of glass may be mixed into the injection. Further, when the syringe needle is thrust through the rubber stopper, minute fragments of the rubber may be mixed into the injection. Mixture of these alien substances into a human body was confirmed by a microscope. Bad influence of these alien substances on the human body is problematic.
In order to solve these problems, the syringe as shown in FIGS. 28(a) and 28(b) was proposed which is disclosed in Japanese Patent Publication No. Sho 62-58745. This syringe, as shown in FIG. 28(a), includes a needle holder 1 on the side of a syringe needle and a cylinder 4 closed at its ends by plungers 2 and 3. The needle holder 1 and the cylinder 4 are fabricated separately, and the space formed by the plungers 2 and 3 is previously filled with an injection. In use, as shown in FIG. 28(b), with the cylinder 4 fit in the needle holder 1, the plunger 3 is pushed toward the side of the needle. Then, the plunger 2 is pushed into the needle holder 1 and the injection flows through a passage 6 formed in the needle holder 1 toward the needle.
This syringe does not require necessity of cutting the ampoule, and hence can solve the problems of bacteria infection due to injury in ampoule cutting and mixture of minute fragments of glass.
This syringe, however, can be applied to only the case where a single kind of injection agent is used. Where two or more injections are to be injected, i.e., a mixed solution of two injections A and B is to be injected, these injections A and B must be mixed previously. In this case, even when the injections A and B are solely present, respectively, and also stable for a long-time preservation, the mixture of injections A and B is difficult to maintain its stability.
The solid antibiotic, steroid and other injections described above is dissolved in a solution and the resultant injection liquid is injected. In an emergent medical scene, doing such an operation is very troublesome. Further, the syringe, which includes the needle holder 1 and the cylinder 4 fabricated separately, is fabricated at high production cost. Disposing such a syringe, therefore, is wasteful.
In order to avoid such an inconvenience, the syringe as shown in FIGS. 29(a) and 29(b) which is disclosed in Japanese Preliminary Publication No. Sho 60-72561 was proposed. The syringe includes a cylinder 10 having a syringe needle connection portion 11 formed at one end and a plunger insertion hole 12 formed at the other end and a plunger 13 inserted from the hole 12. In the cylinder 10, a swelling portion 17 is formed and a partition portion 14 located apart from the swelling portion 17 divides the cylinder 10 into two chambers 15 and 16. The chamber 15 contains injection powder and the chamber 16 is filled with its solution or diluted solution.
In use, when the plunger 13 is pushed, the pressure in the chamber 16 is increased. As a result, the partition portion 14 moves toward the syringe needle to reach the swelling portion 17 as shown in FIG. 29(b). The swelling portion of the cylinder constitutes a passage 17. When the partition portion 14 reaches this portion, the solution contained in the chamber 16 flows into the chamber 15 through the passage 17. As a result, the powder is solved to provide an injection liquid. Thereafter, air remaining in the chamber 15 is discharged from the syringe needle. The resultant injection is given to a patient.
The syringe disclosed in Japanese Preliminary Publication No. Sho 60-72561 can previously contain two different injections or injection agents. A cap 18, which is only one means of sealing the side of the syringe needle, is likely to come off. Therefore, the sealing is unstable and the preservation of the injection agents for a long time is difficult. In using local anesthetic, many clinical doctors say that the effect of a treatment medicine is more manifest in separate injections than in mixed injections. Specifically, it is preferable to first inject local anesthetic without mixing the local anesthetic with a treatment medicine to lose the sense at the affected part, and thereafter inject the treatment medicine.